Doug Rosenberg, who spent much of his career making software for the defense industry and now runs his own consulting outfit, is XP's most vitriolic opponent. He derides its followers as "extremos" and published a book devoted to The Case Against XP. His most damning attacks have been directed at the movement's iconic project: the Chrysler payroll system. It was the first use of extreme programming and is held up by XPers as a monument to the success of the approach. Rosenberg insists on being the voice of sobriety amid the intoxication: The Chrysler system, he reminds the masses, was canceled before it was completed and proved capable of less than a quarter of what was expected of it.

Beck has heard the charges and blames Chrysler for botching the project. Mostly, he dismisses complaints. "Extreme programming is an emotional experience," he maintains. "When you feel it, you understand." Then he adds a typically cheeky metaphor. "Talking about XP and trying it are two different things - like reading The Joy of Sex versus losing your virginity."

That Beck's eccentricities appeal to geeks is no surprise. What's peculiar is that his ideas are spreading into the heartland. George Azrak, senior VP of information systems at Domino's Pizza, remembers exactly how he became a believer in XP. In the fall of 2000, his boss requested a new sales-tracking system for the company, an interface for order takers at 7,000 locations that would handle the annual sale of 400 million pies. The backend had to track everything - toppings, crusts, sodas, sizes, delivery addresses - and, Azrak recalls, "We were supposed to have the first rev ready in nine months."

Sensitive and cheerful, with a Mr. Magoo face and powdery skin, Azrak had been producing software for three decades, and it was clear to him immediately: The job was too big, the time too short. "I knew that with traditional methods, I was doomed to fail." So he brought in XP consultants and hired several devotees of the method.

It worked. Azrak got his point-of-sale system, and he got it on time. The team relied most on the XP rule dubbed the Planning Game, a quaintly low tech approach to scheduling that includes "stories" written on old-fashioned index cards to describe a single feature a customer wants in the software. These scribbled tags replace the voluminous project descriptions of the past, typically written over the course of months (sometimes years) before work begins. An index card might, "Create a Cancel button that ends the current session," or "Add a Percent Change column to the report marketers download from the database" - the kind of task an engineer can code in a few hours. At Domino's, no story was so complex that it couldn't be realized in five days. By working in such small, manageable increments, programmers built the project organically, rather than being lashed to a design hatched at the outset. "There's something magical about XP," Azrak says now.

Tim Wise, who wears his thinning blond hair feathered back á la Saturday Night Fever and carries a 52-ounce Big Gulp into meetings, began doing extreme programming two years before he landed at Domino's. Ask him what's so great about pair programming and he'll give you an evocative analogy. "Say you're in Northern California, and you're driving those windy roads over the hills to Santa Cruz. It's night and it's rainy, and there's a brick wall on one side and a drop on the other. And say you don't know which exit you want, and you're trying to read a map while also watching for signs. Boy, wouldn't you be happy if there was someone beside you? Someone to study the map while you watch the road?"

Or ask Asim Jalis at HP, and he'll muse: "Once you've paired for a while, it's hard to program alone. I feel like my brain's half there."

Or ask a few XP programmers whether this new love of togetherness belies the old myth of the loner geek. Aren't coders supposed to be antisocial - comfortable only when enclosed in their abstract world, far from everything human? Is that image a fiction, made up by jealous outsiders?

No. No one disputes the reality of the awkward, math-minded introvert who doesn't belong. But they'll tell you that he's lonely.

"Thou Shalt Work In Pairs"The 12 commandments of extreme programming

I _ The Planning GameMeet with coders, managers, and the customer each week to schedule tasks for the next phase. Update the plan regularly.

II _ Small ReleasesPut a simple system into production quickly, then release new versions on a short cycle.

III _ MetaphorCreate an analogy that expresses how the parts of the new system work.